Electric indicating instrument



Feb. 4,1930. M. J. Hueems ELECTRIC NDICATI NG INSTRUMENT Filed Feb. '5, i925 3 .m 5 R in/M 0 (R w %w v m 1.1V... W5v

Patented Feb. 4, 1930 UNITED STATES PATENT OFFICE MERION J'. HUGGINS, OF UPPER SADDLE RIVER, NEW JERSEY, 'ASSIGNOR TO AUTO- METER COMPANY, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE ELECTRIC INDICATING INSTRUMENT Application filed February 5, 1925. Serial No. 7,060.

This invention relates to electric indicating instruments such as ammeters, or instruments for measuring the quantity of liquid in a tank embodying a rotatable index drum or dial of cup shape arranged with calibrations upon the periphery thereof to be exposed and read through an opening in the instrument casing, the index drum being positioned by electromagnetic forces generated by a pair of coils acting on an armature of arcuate or ring form of magnetizable material, preferably polarized, carried by the index drum, and it is the object of the present invention to provide improved means for mounting the index drum as well as the supporting of the arcuate member from the drum, and an imroved mounting for the electromagnetic orce generating coils, whereby to provide a more simple and compactly constructed and arranged instrument.

With the foregoing object in view I have illustrated in the drawing an electric instrument embodying the invention wherein Figure 1 is an elevational view of the instrument,

23 partly broken way, to show the arrangementof mounting the instrument carrying casing upon a member constituting a closure and mounting member for the casing.

Figure 2 is a plan view.

Figure 3 is a view looking at the bottom of the closure and mounting member for the casing.

Figure 4 is a cross sectional view to illustrate the mounting of the index drum, the supporting of the armature member therefrom and the mounting of the electromagnetic force generating coils.

Figure 5 is a side elevation of the instrument carrying casing looking at the side opposite to that shown in 'Figure 1.

Figure 6 is a view taken at right angles to Figure 4 to show the mounting and supporting of the armature ring from the indicator drum and the arrangement of the coils with respect to the armature ring.

Figure 7 is a cross sectional view of a coil carrying and mounting spool.

Figure 8 is a plan view of coil spool and support.

Figures 9 and 10 are diagrammatic views a part of the to show circuit arrangements of the energiz- 1ng coils.

In carying out the invention I utilize an instrument carrying casing of rectangular shape in cross section having an opening at one end, and comprising a pair of flanged and releasably connected plates 9, 10. To form the casing the opposite marginal side ortions of the plate 9 are flanged at a right angle to the intermediate ortion, as at 9', and the one end portion 0? the plate 10, to constitute the bottom of the casing, is flanged at a right angle, as at 10', with the opposite sides of said flange portion slightly undercut relative to the width of the body of the plate to fit between the side flanges 9 of the plate 9 the plates being secured in assembled relat1on by nibs formed on and extending from the flanges and bottom edge of the plate 9 and bent about the plate 10, as shown at 11, the nibs extending from the plate flanges 9 also being engaged in notches formed in the edges of the plate 10. The casing is adopted to be releasably mounted and supported at the open end on a mounting member by engaging the same upon flanges 11 arranged about an opening in a mounting plate 12 of said member, the flanges being arranged with resilient tongues to engage in openings in the casing, as at 13 to releasably secure the casing to the supporting flange 11. A second plate 14 is juxtaposed to the plate 12, which is termed an index plate, having an opening 15 with the marginal portions flanged to extend into the casing, as shown at 16, said opening having a transverse rib 17 to serve as an index or pointer for a purpose to be hereinafter described. A transparent plate 18 of celluloid or glass is juxtaposed to the plate 14 to close the opening 15, and the three plates are united into a unitary structure by a bezel or frame 19.

An index drum or dial 20 in the form .of a cup shaped member is arranged with suitable --calibrations upon the periphery and rotatably mounted in the casing by a pintle 21 to expose the calibrations through the window or opening 15 in the mounting member to be read in connection with the index or pointer 17. The drum is flged axially at one end of the pintle by clamping between a pair of 'washers or nuts threaded onto the pintle, as

shown at 22, with the said end of the pintle rotatably engaging in a perforation in the casing plate 9 and having an anti-friction bearing support in the casing at the opposite end, shown as comprising a ball 23 mounted in a cupped member 2 L mounted in the casing member 10 with the end of the pintle resting upon the ball, the instrument being mounted as shown in Figure 4 to extend substantially in a horizontal plane.

An element 25 of arcuate form subtending through an arc of less than 360 degrees, and in the present instance through an are greater than 180 degrees and constructed of magnetizable material, but which may be polarized, is carried by the drum concentrically thereof and substantially centrally of the casing by brackets 26, 27, the bracket 26 being fixed to the ring intermediate the ends, while the bracket 27 is fixed to a mounting member 28 bridging the gap between the ends of the ring. The brackets are suitably secured to the drum, as by riveting soldering or spot welding.

The indicator drum is rotated and positioned under the influence of opposed magnetic forces acting upon the armature element 25, and comprising a pair of coils 29, 30 mounted on the casing plate 32 with the centers of the cores e ually spaced from the axis of the arcuate meii ibenand drum, and spaced apart substantially 180 degrees, the arcuate member subtending through an are so that the same will be positioned within-the zones of influence of both coils in all positions thereof. The coils are adapted to be differentially energized with a resultant dissymmetrical flux distribution and a diflerential'magnetiz'ation of thearcuate member or armature and thereby moving the armature under the magnetic forces generated by one coil against the magnetic forces generated by the other coil. These coils are carried by spools (Figure 7 comprising a core 31, preferably of non-conducting and non-magnetizable material, about which the coil is wound engaged at opposite ends in perforations in plates 32, said plates serving as flanges for the spool and mounting members for the coils. Each of the lates 32 is arranged with a laterally extending nib 33 (Figure 82 adapted to be engaged in perforations in t e casing plate 10 and bent over the face of the plate, as shown at 34-. in Figure 5, the coil supporting plates 32 being constructed and arranged whereby the spool cores will be in a plane so that the ring may engage and have movement in said cores and the coils extend around said ring.

The indicator drum is mounted with the closed end adjacent the casing plate 9 with the'flange of the drum extending adjacent to the casing plate 10 and surrounding the armature element 25 and the energizing coils.

, to screen the magnetic drum actuating means from magnetic and electromotive forces external to the instrument.

The instrument may be connected in different circuit arrangements to adapt it to different purposes. In Figure 9 there is shownin a diagrammatic manner a circuit arrangement to adapt the instrument to function as an ammeter. In this instance the wire of the coils is relatively heavy and the coils comprise only a few turns and each coil has the same number of turns. One terminal of each of the coils is connected with one terminal of a battery, shown in a conventional manner at B, by connecting one terminal of the battery and one terminal of each of the coils to a binding post 35 carried by and insulated from the caslng. The value of the magnetic force generated by one coil, the coil 29 as shown in the illustration, is fixed and less than the value of the magnetic force generated by the coil 30. This is effected by the connecting of a fixed resistance a in the connection of the other terminal of said coil 29 with the other terminal of the battery. This resistance is connected in the circuit of coil 29 by connecting the other terminal of coil 29 to the binding post 36 carried and insulated from the casing, to which post one terminal of the fixed resistance is connected and the other terminal of said resistance being connected with the other terminal of the battery. The other terminal of the coil 30 is also connected to said latter terminal of the battery, and the magnetizing value ofsaid coil is varied by variations in the current flow through said coil effected by a load on the circuit, as by an electric translating device connected in the circuit of said coil and shown in a conventional manner. as lamps I), this being elfected by connecting said terminal of the coil 30 to a binding post 37 carried by and insulated from the casing to which the battery is connected with the interposed translating device I). When the switch 0 is open the current flows through coil 29 and the electromagnetic force generated by the coil influences the armature member to move sa1d member and the indicafor to the left as viewed in Figure 9, and when the switch is operated to close the circuit of coil 30 said latter coil 30 is energized in prov portion to the amount of current consumed by with the instrument described, for instance, when the instrument is utilized for indicating the quantity of liquid in a tank. In said arrangement one terminal of each coil is conposite terminal of the battery is adapted to be moved relative to the resistance device to connect variable amounts of the resistance device into one coil and cut out proportional amounts from the other coil, whereby the coils are differentially energized to generate magnetic forces of variable value one relative to the other and the forces generated by one coil influencing the armature to move the same against the force on the armature generated by the other coil .and thereby move the indicator to variable indicating positions. In the practical use of the instrument for this purpose the contact member d is positioned relative to the resistance element in accordance with the liquid level in a tank containing the liquid to be measured and actuated by means i which rises and falls with the liquid level in the tank.

By thearrangement described, it will be obvious that the casing member 10 serves as a mounting and supporting member for the operative mechanism of the instrument, the coil carriers and pintle carrying theindicator and arcuate element being assembled thereon, when the casing member 9 is connected to the casing member 10,-and thus forming the carrying and enclosing casing for the operative mechanism of the instrument.

1. In an electric indicating instrument, a casing, oppositely disposed electromagnetic force generating coils mounted upon a wall of the casing, an arcuate member of magnetizable material supported in the casing to rotate upon its axis and have movement in a path coincident with the axes of the coils and adapted to be moved under the influences of the electromagnetic forces generated bythe coils, and a cylindrical membernarranged to extend around the coils and participate in the movement of the arcuate member, said i cylindrical member having indicator calibrations arrangedfon the periphery thereof.

2. In an electric indicating instrument, a casing, electromagnetic force generating coils, carriers for said coils arranged with nibs adapted to be engaged in perforations in a casing wall to mount said coils in the eas- 5 ing with the cores of the coils in the same 'Having thus described my invention I plane, a cup shaped member rotatably mounted in the casing centrally between the coils with the flange of said member extending around the coil carriers, said member being arranged with indicator calibrations upon the periphery thereof, and an arcuate member of magnetizable material and subtending through an arc of less than 360 degrees carried by the indicator member concentrically thereof to have movement in a circular path coincident with the axes of the coils and the indicator and arcuate member adapted to be moved under the influence of the forces generated by the coils upon the arcuate mem- 3. In an electric indicating. instrument, an electromagnetic force generating coil, and a carrier therefor comprising a spool core upon which the coil is wound and a pair of perforated plates in which the ends of the core are engaged, said plates being arranged with nibs to mount the same upon the wall of the casing for the instrument.

4 In an electric indicating instrument, a casing, a cup member arranged with calibrations upon the periphery thereof, a pintle upon which said member is mounted adjacent one end and rotatably supported in the casing, an arcuate member carried by the cup member concentric of and in enclosed relation thereto and centrally of the casin and magnetic force generating means to in uence said arcuate member and move the same with the cup member.

5 In an electric indicating instrument, a casing, a cup member arranged with indicator calibrations about the periphery thereof, a pintle upon which said cup member is axially fixed and rotatably mounted in the easing, an arcuate member of magnetizable material carried by and concentrically withinthe cup member and participating in the movement thereof, and magnetic force generating coils having the centers spaced equal distances from the axis of the arcuate member and spaced apart less than 360 degrees, and under the influence of whose magnetic forces the arcuate member and indicator are moved to different indicating positions.

Signed at New York city, in the county of New York and State of New York this 23rd day of January, 1925.

MERION J. HUGGINS. 

